In generally, a washing machine is an appliance used in a house most commonly, which washes clothes, cloth item, articles of clothing and beddings (hereinafter, the laundry) and removes dirt of the laundry by using impact of water, chemical action of detergent and friction force between water current and the laundry through a washing, rinsing and spinning cycle.
The washing machine is, classified into an agitator type washing machine, a pulsator type washing machine and a drum type washing machine. The agitator type washing machine and the pulsator type washing machine have a drum standing vertically, and the drum type washing machine has a drum standing horizontally.
The agitating type washing machine performs washing by using a beating effect created in agitating a washing pole provided in a center of a tub in a right- and left-direction, whereas the pulsator type washing machine performs washing by using a friction force between the laundry and water current caused in agitating a pulsator of a circular plate shape formed in a lower portion of a tub in a right-and-left-direction. The drum type washing machine performs washing by using impact created owing to the drop of the laundry and chemical action of detergent once the laundry, washing water and the detergent are mixedly loaded into a drum having plural lifters projected.
As well-known in the related art, according to the conventional drum type washing machine, a tub holding wash water therein is mounted within a cabinet defining an exterior of the drum type washing machine. Also, a drum having the laundry loaded therein is mounted within the tub and a motor rotating the drum is mounted in rear of the tub. A rotation shaft is hingedly connected to a rear side of the drum with passing through the tub.
Recently, demands for the drum type washing machine have been increasing accordingly, because water consumption, fabric damage and laundry entanglement are much less in the drum type washing machine than in the pulsator washing machine. Moreover, since the drum type washing machine may be adapted to be built-in or be installed as requested by a user, for example, in the kitchen sink and the drum type washing machine is preferred owing to the recent consumption trend, the popularity and the demand for theme have been drastically increasing.
Together with that, although a drum type washing machine with the capacity of 6 to 8 kg has been released a lot, the drum capacity has been getting bigger according to the user wish that he/she wishes to wash bigger beddings or bigger laundries at one time. Especially, a drum type washing machine with a 13 kg drum is popular in the North America and it can be said that a drum type washing machine which was thought as one with small capacity has been getting bigger and bigger.
The drum type washing machine with a bigger capacity accompanies a bigger drum. That is why the capacity of the drum type washing machine is determined by a drum size.
However, it is neither technically nor economically easy to increase the drum size by only increasing a diameter or length of a drum. If the diameter or the length of the drum is increased, a diameter or a length of a tub should be increased, considering the collision between the drum and the tub. Thus, a size of a cabinet should be increased, thereby causing a problem of high production cost and a big size of the whole washing machine bigger than necessary.
That is, although there may be spare room to prevent the collision between the tub and the drum, it is not easy to enlarge a drum size in the same exterior of the conventional drum type washing machine.
Also, it is necessary in reducing the production cost to apply a bigger drum to various parts needed in manufacturing a drum, because the production cost may be increasing as much as extraordinary components which are different from the existing components are needed.
It can be confirmed in a process of developing a drum type washing machine that to enlarge the capacity of the drum type washing machine is not easy. Although European washing machine manufacturers had conquered the international washing machine market until the mid 90'es, their capacity of the drum type washing machine had been limited to 6 kg. That is why a motor of their drum type washing machine fails to control the number of the speed and space for a clutch and a belt is needed.
That is, the conventional drum type washing machine can make the laundry damaged less even with less wash water and enlarging the capacity thereof is limited by the various conditions.